In order to heat and ventilate modern aircraft, flow patterns are set up for the recirculation of cabin air. Effective pathways and barriers which limit the recirculated air result in reducing the quantity of air required and consequently the power necessary to cause the recirculation of this air. A reduction in power results in a conservation of fuel and more cost effective operation of the aircraft. In addition, well designed recirculation barriers limit the passage of smoke, odors and fumes which may be unpleasant or noxious to the crew and passengers.
One area in which a barrier is required to limit the recirculation of air is between the overhead liner of the passenger compartment and the top skin of the aircraft. This overhead passageway is used for air ducting, control wires, hydraulic lines and electrical lines. Various air carriers require different configurations of the aircraft and consequently different hydraulic line and wiring patterns through the overhead passage way and across the air recirculation barrier. Several different recirculation barriers were required to meet the diverse interior wiring patterns. These barriers were costly to produce and in many instances had to be modified at a subsequent date to accommodate additional wiring.
In the past, large bundles of wire or conduits were passed through the air recirculation barrier by penetration seals at designated points. These penetration seals or envelopes are still used to surround large diameter semifixed components as they pass through the barrier. These penetration seals are costly to construct and limit the location of the major components to specific paths. The inventive universal sleeve as used in the air recirculation barrier handles individual wires, small bundles and small hydraulic lines which may have indefinite locations and paths thru the recirculation barrier.
The inventive universal sleeve is designed to permit the use of a single recirculation barrier on several different models of aircraft and to accommodate diverse hydraulic line and wiring patterns. The universal sleeve also permits modifications of the hydraulic and wiring patterns at a later time.
The inventive universal sleeve has a opening to permit random passage of hydraulic lines or wires. The sleeve is comprised of a layer or flap of fabric material which is joined to close off a large hole in the fabric air recirculation barrier. The flap is held together by Velcro edging of hook and pile-type tape. This Velcro tape is continuously applied along the edge of the flap.
When single wires, small bundles or hydraulic lines of small diameter pass through the universal sleeve the holding ability of the Velcro hook and pile ends on the tape are sufficient to seal the opening in the universal sleeve. When larger bundles or tubes, on the order of 1/2 inch in diameter, are used tie straps are looped around the Velcro taped edges and pinch the Velcro around the circumference of the larger bundles or tubes to seal off the flow of air. An air recirculation barrier, which substantially eliminates the passage of any air, smoke or fumes, across the barrier may be constructed by the use of sealing tape applied over the Velcro edge surfaces to close the opening in the universal sleeve.